From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CDCCC5AD4C for ; Wed, 15 Nov 2023 19:21:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233005AbjKOTV1 (ORCPT ); Wed, 15 Nov 2023 14:21:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233256AbjKOTVP (ORCPT ); Wed, 15 Nov 2023 14:21:15 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F65B173B for ; Wed, 15 Nov 2023 11:21:02 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDCD8C433CB; Wed, 15 Nov 2023 19:21:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700076061; bh=oq6b5PEUU1TJlIocnFblYHBsQKs/5x4la6dWPREzl54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qYCWl+K3mdRoK9JDoxYw0bOE4iXma4tgpSvlw6oa0Ofur1Uv3BgCodbSWgGCOQEOW oOf7nC8FzlCUXWd+vfvk4AhOt5JJbZ5qbg7KUhRyibovXZnhEY1ZoL1V8YE6SV6ZoG EwcTBycUn4t9de3g4CfiQlkkw702V8kdQCVoGMTQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Menglong Dong , Yonghong Song , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.5 051/550] bpf, x86: save/restore regs with BPF_DW size Date: Wed, 15 Nov 2023 14:10:35 -0500 Message-ID: <20231115191604.229307603@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191600.708733204@linuxfoundation.org> References: <20231115191600.708733204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Menglong Dong [ Upstream commit 02a6dfa8ff43efb1c989f87a4d862aedf436088a ] As we already reserve 8 byte in the stack for each reg, it is ok to store/restore the regs in BPF_DW size. This will make the code in save_regs()/restore_regs() simpler. Signed-off-by: Menglong Dong Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230713040738.1789742-2-imagedong@tencent.com Signed-off-by: Alexei Starovoitov Stable-dep-of: 2b5dcb31a19a ("bpf, x64: Fix tailcall infinite loop") Signed-off-by: Sasha Levin --- arch/x86/net/bpf_jit_comp.c | 35 ++++++----------------------------- 1 file changed, 6 insertions(+), 29 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 438adb695daab..fcbd3b7123a47 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1860,57 +1860,34 @@ st: if (is_imm8(insn->off)) static void save_regs(const struct btf_func_model *m, u8 **prog, int nr_regs, int stack_size) { - int i, j, arg_size; - bool next_same_struct = false; + int i; /* Store function arguments to stack. * For a function that accepts two pointers the sequence will be: * mov QWORD PTR [rbp-0x10],rdi * mov QWORD PTR [rbp-0x8],rsi */ - for (i = 0, j = 0; i < min(nr_regs, 6); i++) { - /* The arg_size is at most 16 bytes, enforced by the verifier. */ - arg_size = m->arg_size[j]; - if (arg_size > 8) { - arg_size = 8; - next_same_struct = !next_same_struct; - } - - emit_stx(prog, bytes_to_bpf_size(arg_size), - BPF_REG_FP, + for (i = 0; i < min(nr_regs, 6); i++) + emit_stx(prog, BPF_DW, BPF_REG_FP, i == 5 ? X86_REG_R9 : BPF_REG_1 + i, -(stack_size - i * 8)); - - j = next_same_struct ? j : j + 1; - } } static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_regs, int stack_size) { - int i, j, arg_size; - bool next_same_struct = false; + int i; /* Restore function arguments from stack. * For a function that accepts two pointers the sequence will be: * EMIT4(0x48, 0x8B, 0x7D, 0xF0); mov rdi,QWORD PTR [rbp-0x10] * EMIT4(0x48, 0x8B, 0x75, 0xF8); mov rsi,QWORD PTR [rbp-0x8] */ - for (i = 0, j = 0; i < min(nr_regs, 6); i++) { - /* The arg_size is at most 16 bytes, enforced by the verifier. */ - arg_size = m->arg_size[j]; - if (arg_size > 8) { - arg_size = 8; - next_same_struct = !next_same_struct; - } - - emit_ldx(prog, bytes_to_bpf_size(arg_size), + for (i = 0; i < min(nr_regs, 6); i++) + emit_ldx(prog, BPF_DW, i == 5 ? X86_REG_R9 : BPF_REG_1 + i, BPF_REG_FP, -(stack_size - i * 8)); - - j = next_same_struct ? j : j + 1; - } } static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, -- 2.42.0